Apparatus for imaging a tissue region

Abstract

The present invention is directed to a novel multi-spectral exogenous fluorescence polarization imaging technique that enables rapid imaging of large tissue fields. The imaging device includes a tunable monochromatic light source and a CCD camera. Linear polarizers are placed into both the incident and collected light pathways in order to obtain fluorescence polarization or/and anisotropy image. To acquire exogenous fluorescence image, fluorescent contrast agents are delivered to a target tissue.

1 - 13 . (canceled) 
     
     
         14 . An apparatus for imaging a tissue region comprising:
 a polarized light source of a first wavelength band providing light to the tissue region, wherein the light has a first polarization;   at least one detector operable to detect first light of a second wavelength band emanating from the tissue region of the first polarization as well as second light emanating from the tissue region of a second polarization, wherein the second polarization is approximately perpendicular to the first polarization; and   a computer operable to form an image based on the first and second light received by the at least one detector.   
     
     
         15 . The apparatus of  claim 14 , wherein the tissue region is treated with a contrast agent prior to formation of the image. 
     
     
         16 . The apparatus of  claim 15 , wherein the contrast agent is introduced in a manner selected from the group of: internally into the tissue region by injection; internally into the tissue region by ingestion; topical application; and combinations thereof. 
     
     
         17 . The apparatus of  claim 15 , wherein light detected prior to application of the contrast agent is used in conjunction with light detected during or after the application of the contrast agent to form a second image. 
     
     
         18 . The apparatus of  claim 14 , wherein the at least one detector incorporates a polarization selection device. 
     
     
         19 . The apparatus of  claim 14 , wherein the at least one detector includes first and second detectors, wherein the first detector is operable through a first output of a beam splitter to detect the first light and the second detector is operable through a second output of the beam splitter to detect the second light. 
     
     
         20 . A method of determining characteristics of a tissue region comprising the steps of:
 applying a known intensity of incident light polarized in a first polarization and of a first wavelength to a surface of the tissue region;   detecting light of a second wavelength of the first polarization and a second polarization, wherein the polarizations are approximately perpendicular; and   using a relationship between at least two factors to determine a characteristic of the tissue region, wherein the at least two factors are selected from the group consisting of: i) the known intensity of the incident light; ii) the detected light of the second wavelength and the first polarization; and iii) the detected light of the second wavelength and the second polarization.   
     
     
         21 . A method of determining fluorescence depolarization characteristics of a tissue region comprising the steps of:
 a) illuminating the tissue region with polarized excitation light; and   b) comparing fluorescence emission at two substantially perpendicular polarizations, wherein one of the two substantially perpendicular polarizations corresponds to the polarized excitation light; and   c) determining a characteristic of the tissue region based upon the comparing step b).   
     
     
         22 . The method as recited in  claim 21 , wherein the comparing step includes form a spatially referenced image. 
     
     
         23 . The method as recited in  claim 21 , wherein the characteristic is used to evaluate cancer during surgery. 
     
     
         24 . The method as recited in  claim 21 , further comprising the steps of:
 d) comparing backscattered excitation light from the tissue region and fluorescence emission from the tissue region at two substantially perpendicular polarizations, wherein one of the two substantially perpendicular polarizations corresponds to the polarized excitation light; and   e) determining a characteristic of the tissue region based upon the comparing step d).